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L. A. LAYNE Feb. 14, 1956 METHOD AND APPARATUS FOR REPAIRING BROKENCASING IN WELL BORES Filed March 2. 1953 3 Sheets-Sheet 1 e 2 m M 4 3 76 5 WW I V f I f gm m W33: Ev I A m I wfli A e Wage h s e .lTLLI 1 L. A.LAYNE Feb. 14, 1956 METHOD AND APPARATUS FOR REPAIRING BROKEN CASING INWELL BORES 3 Sheets-Sheet 2 Filed March 2, 1953 .I: II- II I llili Iccvcc Leflle A. Lay/7e INVENTOR.

ATTORNEY L- A. LAYNE Feb. 14. 1956 METHOD AND APPARATUS FOR REPAIRINGBROKEN CASING IN WELL BORES 5 Sheets-Sheet 3 Filed March 2. 1953 Les/1eA. Lay/7e INVENTOR.

yp mg /4 7'7'ORNE Y METHOD AND APPARATUS FOR REPAIRING BROKEN CASING INWELL BORES Leslie A. Layne, Houston, Tex.

Application March 2, 1953, Serial No. 339,797

4 Claims. (Cl. 166-14) The invention concerns a method and an apparatusfor repairing broken casing, in place, in well bores.

It is an object of the invention to provide a method and means forrealigning the portions of the casing immediately adjacent the break andfor forming a rigid and secure joint permanently connecting the brokenportions of the casing.

The invention contemplates a hydraulically expansible tool comprising avertically disposed cylinder of smaller diameter than the insidediameter of the casing, the cylinder having a valved lower end andhaving a cylindrical wall section capable of being deformed outwardly bythe application of fluid pressure, which may be lowered into the casingto the point where the break occurs and thereafter expanded by fluidpressure whereby the portions of the casing immediately adjacent thebreak are realigned with each other.

The invention further contemplates a hydraulically expansible tool ofthe type described which may be used also as a cementing plug. Theinvention contemplates first realigning the portions of the casingimmediately adjacent the break, in the manner described, and thereafterperforating the adjacent area of the casing, as well as the cylindricalwall section of the tool, and forcing cement into the annulus betweenthe formation and the easing, thru the perforations.

An advantageous feature of the invention is that the portions of thecasing immediately adjacent the break may be realigned, and thereafterthe adjacent area of the casing may be perforated, and cement forcedinto the annulus between the formation and the casing, through theperforations, in a single operation, without removing the tool from thehole.

Another advantageous feature of the invention is that it permits theconnecting tubing to be withdrawn from the well bore, after depositingcement therein as above described, while causing the cement to bemaintained under hydraulic pressure during such period of time as may berequired for the cement to set. Thereafter the excess cement is drilledfrom the inside of the casing, and the tool itself is likewise removedfrom the casing by drilling. If desired the cylindrical wall section ofthe tool may be left in place to reenforce the resulting joint.

The invention will be readily understood by referring to the followingdescription and the accompanying drawing, in which:

Fig. 1 is a diagrammatic view in elevation showing the broken casing,with a tool embodying the invention about to be lowered into positionfor repairing the break in the casing.

Fig. 2 is a diagrammatic view in elevation showing the tool in operativeposition, the tool being rotated 180 degrees from the position shown inFig. 1 whereby its tapered lower end may be readily inserted in thelower portion of the casing, which may not be aligned with the upperportion.

Fig. 3 is a sectional view in elevation showing the cynited StatesPatent "ice lindrical wall section of the tool in expanded position andthe adjacent portions of the casing in alignment with each other.

Fig. 4 is a sectional view in elevation showing the step of perforatingthe adjacent area of the casing and the cylindrical wall section of thetool.

Fig. 5 is a sectional view in elevation showing the step of forcingcement into the annulus between the casing and the formation, throughthe perforations.

Fig. 6 is a sectional view in elevation showing the step of drilling theexcess cement, and the tool itself, from the inside of the casing.

Fig. 7 is a sectional view in elevation showing a modified form of theapparatus shown in Figs. 1 to 6, inelusive.

Fig. 8 is a sectional view in elevation, taken at right angles to theview shown in Fig. 7, showing the connecting tubing detached from theremainder of the apparatus. I

Referring to the drawing, a broken casing is shown disposed in a wellbore. The well bore is designated by the numeral 1 and the portions ofthe casing above and below the break are indicated by the numerals 2 and3, respectively. As shown in Fig. l, the portions 2 and 3 are notaligned with each other.

The hydraulically expansible tool of the invention comprises avertically disposed cylinder having a diameter smaller than the insidediameter of the casing, the cylinder having a valved lower end, ashereinafter described, and a cylindrical wall section which is capableof being deformed outwardly by the application of fluid pressure. Thecylindrical wall section, designated by the numeral 4, may be made of asuitable metal or alloy, such as mild steel or aluminum, which may bedeformed under pressure without bursting. The lower end of the cylinderis at least partly closed by an end member 5, which is secured to thecylindrical wall section 4 and has a central opening 6 formed thereinfor the circulation of drilling fluid. The inner surface of the endmember 5 is curved downwardly and inwardly adjacent the central opening6 to form a valve seat for a ball valve 7, which may be dropped into thecylinder from the surface.

The upper end of the cylindrical wall section 4 is connected to acylindrical wall section 8. The cylindrical wall section 8 is made of ametal or alloy having a greater tensile strength than the cylindricalwall section 4, so that it retains its shape while the cylindrical wallsection 4 is being expanded.

For use in setting the tool in the well, and for other purposes ashereinafter described, the cylindrical wall section 8 is detachablysecured to the lower end of a string of tubing 9. A collar Iii issecured to the lower end of the tubing 9, and a sealing ring 11, whichis connected to the lower end of the collar 10 and extends downwardlyand outwardly therefrom for engagement with the cylindrical wall section8 whereby a fluid tight connection is maintained between the collar 10and the cylindrical wall section 8. A pair of diametrically opposed pins12 extend outwardly from the collar 10 for engagement by a pair ofJ-shaped slots 13 which are formed in the cylindrical wall section 8,adjacent the upper edge thereof, whereby the cylindrical wall section 8is detachably secured to the collar 10.

As illustrated in Figs. 1, 2 and 3, the tapered end member 5 serves as aguide for inserting the tool in the lower portion 3 of the casing, whichmay not be aligned with the upper portion 2. The tool is lowered in thecasing to the point where the break occurs, and is disposed partlywithin the upper portion 2 and partly within the lower portion 3 of thecasing. The ball valve 7 is seated, and fluid pressure is applied to thetool, through the tubing 9, whereby the cylindrical wall section 4 isexpanded so that it engages the walls of the casing above and below theavageso break, causing the portions 2 and 3 to be realigned with eachother. Upon releasing the pressure the cylindrical wall section 4retains the portions 2 and 3 in their proper relative positions.

As illustrated in Fig. 4, a perforating gun 14 may be lowered into thewell on a wire line 15, through the tubing 9, so that it is disposedwithin the tool above described. Upon discharging the gun 14perforations 16 may be formed in the adjacent area of the portions 2 and3 of the casing, as well as in the cylindrical wall section 4, theperforations 16 extending also into the formation surrounding the wellbore 1.

As illustrated in Fig. 5,'the perforating gun 14 may be withdrawn andcement may be forced under pressure into the annulus between the wellbore 1 and the portions 2 and 3 of the casing, through the perforations16. Cement is supplied to the tool through the tubing 9, and the cementpreferably is maintained under hydraulic pressure for a period of from24' to 72 hours, until the cement sets.

As illustrated in Fig. 6, the tubing 9 is finally withdrawn and theexcess cement is drilled from the inside of the casing, using a suitabletool 17. The cylindrical wall sections 4' and 8, and the end member 5,likewise may be removed from the casing by drilling. If desired thecylindrical wall section 4 may be left in place to reenforce theresulting joint.

Referring to Figs. 7 and 8, a back pressure valve as described andclaimed in the application of Louis C. Mundt, Serial No. 305,493, filedAugust 20, 1952, is incorporated in the apparatus. The back pressurevalve comprises a resilient, tubular body member 18, one end of the bodymember 18 being secured to a rigid annular member 19 and an elastic,self sealing opening 20 being formed in the end of the body member 18opposite the annular member 19. The annular member 19 is secured to thecylindrical wall section 4 adjacent the point where the cylindrical wallsections 4 and 8 are connected, and the arrangement is such that thelower end of the tubing 9, below the collar 10, may be inserted throughthe elastic, self sealing opening 20. This arrangement permits thetubing 9 to be withdrawn, as shown in Fig. 8, immediately following thestep of forcing cement into the annulus between the bore of the well andthe casing, while maintaining the cement under substantial fluidpressure until suflicient time has elapsed to cause it to set.

The invention may be modified in various ways without departing from thespirit and scope thereof.

I claim:

1. In a method of repairing broken casing, in Well bores, thecombination of steps comprising lowering into the casing a hydraulicallyexpansible tool comprising a vertically disposed cylinder of smallerdiameter than the inside diameter of the casing and having a cylindricalwall section which is capable of being deformed outwardly by theapplication of fluid pressure, disposing the tool within the casing atsuch elevation that the cylindrical Wall section extends from a pointabove the break to a point below the break, and expanding thecylindrical wall section by fluid pressure whereby the portions of thecasing irrilmediately adjacent the break are aligned with each ot er.

2. In a method of repairing broken casing, in well bores, thecombination of steps comprising loweringv into the easing ahydraulically expansiole tool comprising a vertically disposed cylinderof smaller diameter than the inside diameter of the casing and having acylindrical wall section which is capable of being deformed outwardly bythe application of fluid pressure, disposing the tool within the casingat such elevation that the cylindrical wall section extends from a pointabove the break to a point below the break, expanding the cylindricalwall section by fluid pressure whereby the portions of the casingimmediately adjacent the break are aligned with each other, perforatingthe adjacent area of the casing, as well as the cylindrical wall sectionof the tool, forcing cement into the annulus between the formation andthe casing, through the perforations, and thereafter removing excesscement, and at least a part of the tool, from the inside of the casingby drilling.

3. 1n apparatus for repairing broken casing, in well bores, thecombination of a vertically disposed cylinder of smaller diameter thanthe inside diameter of the casing, the cylinder having a cylindricalwall section which is capable of being deformed outwardly by theapplication of fluid pressure, the lower end of the cylinder being atleast partly closed by an end member having a central opening formedtherein for the circulation of drilling fluid, the inner surface of theend member being curved downwardly and inwardly adjacent the centralopening to form a valve seat for a ball valve, the end member beingtapered downwardly to one side whereby it may be used as a wedge tofacilitate inserting the tool in the portion of the casing below thebreak.

4. In apparatus for repairing broken casing, in well bores, thecombination of a vertically disposed cylinder of smaller diameter thanthe inside diameter of the casing, the cylinder having a cylindricalwall section which is capable of being deformed outwardly by theapplication of fluid pressure, and means for applying fluid pressure tothe cylinder comprising a string of tubing disposed within the casingand extending downwardly into the cylinder, means for detachablyconnecting the tubing to the upper end of the cylinder, and means foreffecting a fluid tight seal between the tubing and the cylindercomprising a back pressure valve disposed in the annulus between thecylinder and the tubing, the back pressure valve comprising a resilient,tubular body member, one end of the body member being secured to a rigidannular member which in turn is secured to the cylinder, and an elastic,self sealing opening being formed in the end of the body member oppositethe annular member, the arrangement being such that the lower end of thetubing may be inserted through the elastic, self sealing opening and maybe withdrawn therefrom while maintaining the cylinder under substantialfluid pressure.

References fitted in the file of this patent UNITED STATES PATENTSaural-

